Ground covering support structure

ABSTRACT

A ground covering support structure is provided comprising a plurality of longitudinally aligned boards secured to one another using a plurality of transversely extending rods; and at least one aperture formed in the access mat, the at least one aperture being aligned with a corresponding one of the rods such that an exposed portion of the corresponding one of the rods passes through the aperture, each the at least one aperture containing a retractable lifting link, the retractable lifting link comprising a lifting eyelet and an elongated slot; wherein the rod passes through the elongate slot to restrict movement of the link through the aperture. The boards may advantageously be constructed using recycled beetle kill lumber or similar recycled materials.

This application claims priority from U.S. Provisional Application No. 60/917,280 filed on May 10, 2007, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The following relates generally to ground covering support structures and has particular utility in providing temporary roadways or around cover for large, outdoor work areas such as at a well site or a construction site.

BACKGROUND

In remote and unstable environments, a stable roadway (or any roadway) may not exist. Temporary roadways are sometimes assembled by aligning planks, boards or “mats” along a desired path. Such temporary roadways or otherwise ground covering support structures are commonly referred to as access rig or oilfield mats. The mats enable trucks and other equipment to drive over, store equipment on, or create camp sites on otherwise unstable land by providing a relatively level and stable surface.

Where many access mats are required to build a temporary roadway, it can be onerous to transport and assemble the mats into position. Some prior access mats such as those shown in U.S. Pat. Nos. 4,600,336 to Waller, Jr.; 5,713,695 to Rogers and U.S. Publication No. 2006/0034654 to Sanders; provide lifting points, however, these lifting points can either be difficult to access or may provide a trip hazard when protruding from the upper surface.

Where the lifting points are difficult to access, the loading/unloading, and moving of the mats can be hindered, and trip hazards can create unsafe working environments.

It is therefore an object of the following to obviate or mitigate the above-mentioned disadvantages.

SUMMARY

In one aspect, there is provided a ground covering support structure comprising a plurality of longitudinally aligned boards secured to one another using, a plurality of transversely extending rods; and at least one aperture formed in the support structure, the at least one aperture being aligned with a corresponding one of the rods such that an exposed portion of the corresponding one of the rods passes through the aperture, each the at least one aperture containing a retractable lifting link, the retractable lifting link comprising a lifting eyelet and an elongated slot; wherein the rod passes through the elongate slot to restrict movement of the link through the aperture.

In another aspect, there is provided a ground covering support structure comprising a plurality of longitudinally aligned boards secured to one another using a plurality of transversely extending rods; and at least one aperture formed in the support structure, the at least one aperture being aligned with a corresponding one of the rods such that an exposed portion of the corresponding one of the rods passes through the aperture.

In yet another aspect, there is provided a ground covering support structure comprising at least one aperture formed therein, each the at least one aperture containing a retractable lifting link secured therein by a rod passing therethrough, the retractable lifting link comprising a lifting eyelet and an elongated slot; wherein the rod passes through the elongate slot to restrict movement of the link through the aperture.

In yet another aspect, there is provided a retractable lifting link to permit lifting a ground covering support structure, the lifting link comprising a lifting eyelet and an elongated slot to enable the lifting link to be secured within an aperture in the support structure by a rod passing therethrough such that movement of the lifting link through the aperture is restricted.

In yet another aspect, there is provided a ground covering support structure comprising at least one board constructed of a recycled material such as beetle kill lumber, plastic or rubber.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will now be described by way of example only with reference to the appended drawings wherein:

FIG. 1 is a perspective view of an access mat.

FIG. 2 is an enlarged perspective view of portion A shown in FIG. 1.

FIG. 3 is an elevation view of the access mat of FIG. 1.

FIG. 4 is a plan view of the access mat of FIG. 1.

FIG. 5 is a pictorial view showing the unloading of the access mat of FIG. 1.

FIG. 6 is an assembly view showing portion A of FIG. 1 with a lifting link.

FIG. 7 is a plan view of the lifting link of FIG. 6.

FIG. 8 is a sectional view along the line B-B in FIG. 2.

FIG. 9 is the sectional view of FIG. 8 assembled with the lifting link of FIG. 7 in one configuration.

FIG. 10 is the sectional view of FIG. 9 in another configuration.

FIG. 11 is a partial plan view of another embodiment.

FIG. 12 is a sectional view of portion A along line B-B in yet another embodiment.

FIG. 13 is a partial perspective view of the portion shown in FIG. 12.

FIG. 14 is a sectional view of portion A along line B-B in yet another embodiment.

FIG. 15 is an enlarged portion of the plan view shown in FIG. 4.

FIG. 16 is an exploded perspective view of a rod.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring now to FIG. 1, an access mat 10 is constructed from a series of longitudinally aligned boards 12 attached to each other. It will be appreciated that the access mat may be generally considered as a ground covering support structure that can be used to create temporary roadways as well as any outdoor work area such as at a well site or a construction site.

The boards 12 are preferably made from a recycled material such as beetle kill lumber e.g.—Douglas Fir or pine, which is relatively inexpensive and can be salvaged and reused for additional environmental benefits. It will be appreciated that recycled plastics or rubber materials can also be used, as well as new materials depending on the application and/or expected environment. The boards 12 are attached by a series of transversely extending rods 16. In the example shown in FIG. 1, four rods 16 are used. Aligned with the endmost rods 16, a series of apertures 14 are formed in selected boards 12. In the arrangement shown in FIG. 1, four apertures 14 are formed in the corner portions of the mat 10 such that the intersection of lines passing diagonally across the mat 10 is approximately in alignment with the centre of the mat 10. Such an alignment is used to balance lifting loads as will be explained below. Preferably, the apertures 14 are symmetrically spaced as shown in FIG. 1.

The apertures 14 may be cut or mortised through the middle portion of the boards 12 as shown in FIGS. 1, 2 and 4 or may be cut or mortised as notches 14 a along one edge of the board 12 as shown in FIG. 11. The notches 14 a simplify construction of the selected boards 12 by reducing the number of cuts made and/or simplifying the machinery required to create the apertures 14. The apertures 14 may also comprise an inwardly and downwardly angled bevel 28 cut around the perimeter of the opening on the upper surface of the board 12 as shown in FIGS. 12 and 13 (referred to hereinafter as aperture 14 b). A similar gouge or partial bevel along one edge of the aperture 14 may also be used.

When aligned, the boards 12 may be secured to each other along their respective lengths by drilling through the boards and embedding the rods 16. As can be seen in FIGS. 15 and 16, in one embodiment, the rods 16 are threaded at one end to accommodate a nut 17 and link (not shown) and are given a bent portion 19 at the other end. When assembled, the holes in the board 12 at one end can be countersunk to accommodate the nut 17 and a routered pocket 21 can be cut into the board 12 at the other end such that the bent portion 19 countersinks into the board 12 when the nut 17 is tightened on the rod 16. The bent portion 19 enables the mat 10 to be assembled by tightening at only one end rather than having to tighten at both ends. Since it is preferable to countersink the nut 17, only having to tighten one end increases the efficiency of the assembly process. It has been found that 1″ rods and up to 1¼″ holes provides an adequate fit between the boards 12 and the rod 16.

The endmost rods 16 are aligned with the apertures 14 such that an exposed portion 18 of the respective rods 16 pass substantially through the centre of the aperture 14 as shown in FIGS. 2 and 4. As can be seen in FIG. 3, when assembled, the access mat 10 can provide a stable surface atop a region of underlying material 20 such as earth or stones. The mats 10 can be placed end to end to form a temporary roadway over such underlying material 20.

The apertures 14 can be sized such that the exposed portions 18 of the rods 16 provide a set of lifting points. For such an embodiment, the apertures 14 would be sized to accommodate an appropriately sized hook or other attachment mechanism.

In another embodiment illustrated pictorially in FIG. 5, a transport vehicle 23 having a crane with lifting cables 25 (or other similar lifting apparatus) can rely on a series of retractable lifting links 22 that can be retrieved from the apertures 14 to hoist the access mat 10. As can be seen in FIG. 6, the links 22 can be attached to the mat 10 by inserting the rods 16 through an elongated slot 26 such that the link 22 pulls against the exposed portion 18 to thereby lift the mat 10. The link 22 also provides a lifting eyelet 24 or other suitable aperture, hole or slot to accommodate the attachment of a hook or lifting mechanism. The link 22 is also shown in FIG. 7. It can be seen by referring to FIGS. 7 through 10 that the elongated slot 26 permits the link 22 to be pulled out from the aperture 14 for lifting, and permits the link 22 to be hidden within the board 12 when not in use. In this way, when the access mat 10 is in situ, the link 22 does not create a trip hazard. However, the link 22 is readily accessible when the mat 10 is to be lifted and/or transported.

It can be appreciated that the apertures 14, 14 a, 14 b can be sized to restrict pivotal movement of the links 22 about the rods 16 as shown best in FIGS. 9 and 10 or may be sized similar to the proportions shown in FIG. 6 to permit a predefined amount of pivotal movement as shown in FIG. 14. In order to adjust the amount of pivotal movement permitted, the rods 16 can be realigned towards the upper surface of the mat 10 and the apertures 14 b with bevel 2S used to provide additional maneuverability. The pivotal rotation enables the link 22 to naturally align with the tension forces in the lifting cables 25 to reduce wear and stress on the boards 12 when the mat 10 is being lifted. A similar gouge or partial bevel may instead be provided along only one edge of the aperture 14 so as to provide better access to the link 22.

As noted above, the access mat 10 can be constructed of a recycled product such as beetle kill lumber such as Douglas fir or pine that has been found to be capable of withstanding approximately 30,000 lbs or more. Other materials may instead be selected to accommodate different loads in different environments. The advantages of using beetle kill lumber or similar waste products is that the material may be relatively inexpensive to acquire and provides an environmental benefit. Where the access mats 10 are to be constructed for temporary use and discarded later, the use of a recycled cost effective material is also desirable.

As can be seen in FIG. 1, a radio frequency identification (RFID) tag 7 can be embedded into the access mats 10 in a routered pocket 8 to enable the access mats 10 to be included in an inventory system (not shown). The RD tags 7 provide an owner and/or renter of the mats 10 with a unique identification serial number for each individual mat 10. Where many mats 10 are being used and/or rented, this enables the tracking and reconciliation of the inventory. In this way, e.g., as mats 10 are unloaded off of the vehicle 23, an REID reader (not shown) can record each mat 10 that is placed at that particular job site. Therefore, inventory associated with that job site can be recorded for later referral, billing, etc. As mats 10 are later loaded back onto the vehicle 23, they can again be scanned or read to ensure that all mats 10 are accounted for. It will be appreciated that the RFID tags 7 can be active or passive and other tracking devices such as barcodes (not shown) could similarly be used. Although the REID tag 7 is shown as being embedded on the side of the mat 10, it will be appreciated that it may be embedded on the top, bottom, end etc. Preferably, the RFID tags 7 are sealed in the pocket 8 using a suitable adhesive or epoxy for protection, waterproofing and to not degrade the signals.

To assemble the access mat 10, each board 12 is drilled to accommodate the rods 16 whereby one hole is drilled in each board 12 for each rod 16. A drilling station can be used with a drill press for each hole to ensure a consistent spacing between the holes. The holes for the appropriate board 12 are then counter sunk to accommodate the nuts 17 at one end of the mat and the board 12 for the other end of the mat 10 is routered to provide the appropriate number of pockets 21. The appropriate selection of boards 12 are then cut or mortised to form a series of apertures 14, which may be notches 14 a or complete passages and may include a bevel 28 or gouge for accessing the link 22.

The boards 12 consequently comprise a series of holes of which one hole is aligned substantially centrally across each aperture 14 as shown in FIG. 2. Also, as shown in FIGS. 15 and 16, the appropriate board 12 includes countersunk holes and the appropriate board includes routered pockets 21 for containing the bent portions 19. It will be appreciated that there may be any number of apertures 14 and any number of rods 16 with corresponding countersinks and pockets 21. However, the symmetrical arrangement shown in FIG. 1 is preferred.

In each aperture 14, a link 22 may then be placed with the lifting eyelets 24 facing up such that when the rods 16 are embedded or fed into the boards 12, the exposed portions 18 of each pass through the respective elongated slots 26. The rods 16 are fed through the boards 12 by inserting the threaded end into the pocketed board and then through the remaining board until it emerges at the other side of the mat 10 where the nut 17 is tightened thus countersinking the rod 16 at both ends. As the rods 16 are embedded, the boards 12 are preferably secured against each other longitudinally and a suitable adhesive may be used to strengthen the assembly if desired. When assembled, the boards 12 may be trimmed at each end to provide flush end faces to accommodate end-to-end alignment.

The mat 10 may be lifted onto the vehicle 23 as shown in FIG. 5, by first retrieving each link 22 from the respective aperture 14 and attaching the corresponding lifting cable 25 using the exposed lifting eyelet 24 when in the position shown in FIG. 6, FIG. 9 or FIG. 14. The link 22 may be retrieved using a screwdriver, similar prying bar or even pulled out by the operator depending on the nature and size of the aperture 14. For example, the aperture 14 b having a bevel 28 or similar gouge along one side may better accommodate a prying bar or screwdriver by offering a clear angle towards the lifting eyelet 24. In another example, the aperture 14 may be sized to provide enough peripheral room to enable the operator to grip the link 22. It will be appreciated that the lifting eyelet 24 may be any suitable shape such as generally circular as shown, oval/elliptical etc.

Once each link 22 has been retrieved and attached to the lifting cables 25, the vehicle may then lift the mat 10 onto a flatbed or other surface for transport. When the cables 25 are detached, the links 22 simply slide into the apertures 14 leaving a substantially flush upper surface enabling several mats 10 to be stacked atop each other without becoming unstable. When unloading, a similar process can be followed.

It can therefore be seen that the link 22 can be hidden when not in use and readily retrieved for lifting and/or transportation. The link 22 does not present a trip hazard yet greatly aids in the handling of the access mats 10. It will be appreciated that although preferably used with a set of corresponding links 22, the access mats 10 as shown in FIGS. 1, 3 and 4 may also be used without the links 22 if so desired. It will also be appreciated that the boards 12 may also be used with any suitable material that can withstand the anticipated weight of the machinery expected to cross the temporary pathway or roadway.

Although the invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention as outlined in the claims appended hereto. 

1. A ground covering support structure comprising a plurality of longitudinally aligned boards secured to one another using a plurality of transversely extending rods; and at least one aperture formed in said access mat, said at least one aperture being aligned with a corresponding one of said rods such that an exposed portion of said corresponding one of said rods passes through said aperture, each said at least one aperture containing a retractable lifting link, said retractable lifting link comprising a lifting eyelet and an elongated slot; wherein said rod passes through said elongate slot to restrict movement of said link through said aperture.
 2. The support structure according to claim 1, said at least one aperture extending through a respective one of said boards.
 3. The support structure according to claim 1, said at least one aperture being cut as a notch along one side of a respective one of said boards such that one wall of said aperture is provided by an adjacent board.
 4. The support structure according to claim 1, said at least one aperture comprising a bevel along at least a portion of one edge.
 5. The support structure according to claim 1, said at least one aperture being sized substantially similar to said lifting link to restrict pivotal movement thereof.
 6. The support structure according to claim 1, said at least one aperture being longer in the longitudinal dimension of said board than the width of said link such that pivotal movement of said link is accommodated.
 7. The support structure according to claim 6, said at least one aperture comprising a bevel.
 8. The support structure according to claim 1, said at least one board being constructed of a recycled material such as beetle kill lumber, plastic or rubber.
 9. The support structure according to claim 1 wherein said link is formed as an elongate member rounded at each end, said lifting eyelet being, formed at one end and said elongated slot being extending from the other end towards said eyelet.
 10. The support structure according to claim 1 wherein said corresponding one of said rods passes through substantially the centre of said at least one aperture.
 11. The support structure according to claim 1 wherein said rod is threaded at one end to accommodate a nut and is bent at another end to retain said rod.
 12. The support structure according to claim 1 further comprising a radio frequency identification tag affixed thereto.
 13. A ground covering support structure comprising a plurality of longitudinally aligned boards secured to one another using a plurality of transversely extending rods; and at least one aperture formed in said access mat, said at least one aperture being aligned with a corresponding one of said rods such that an exposed portion of said corresponding one of said rods passes through said aperture.
 14. The support structure according to claim 13 wherein said corresponding one of said rods passes through substantially the centre of said at least one aperture.
 15. The support structure according to claim 13, said at least one aperture extending through a respective one of said boards.
 16. The support structure according to claim 13, said at least one aperture being cut as a notch along one side of a respective one of said boards such that one wall of said aperture is provided by an adjacent board.
 17. The support structure according to claim 13, said at least one aperture comprising a bevel along at least a portion of one edge.
 18. The support structure according to claim 13, said at least one aperture being sized substantially similar to said lifting link to restrict pivotal movement thereof.
 19. The support structure according to claim 13, said at least one aperture being longer in the longitudinal dimension of said board than the width of said link such that pivotal movement of said link is accommodated.
 20. The support structure according to claim 19, said at least one aperture comprising a bevel.
 21. The support structure according to claim 13, said at least one board being constructed of a recycled material such as beetle kill lumber, plastic or rubber.
 22. The support structure according to claim 13 wherein said rod is threaded at one end to accommodate a nut and is bent at another end to retain said rod.
 23. The support structure according to claim 13 further comprising a radio frequency identification tag affixed thereto.
 24. A ground covering support structure comprising at least one aperture formed therein, each said at least one aperture containing a retractable lifting link secured therein by a rod passing therethrough, said retractable lifting link comprising a lifting eyelet and an elongated slot; wherein said rod passes through said elongate slot to restrict movement of said link through said aperture.
 25. The support structure according to claim 24, said at least one aperture extending through a respective one of said boards.
 26. The support structure according to claim 24 wherein said link is formed as an elongate member rounded at each end, said lifting eyelet being formed at one end and said elongated slot being extending from the other end towards said eyelet.
 27. The support structure according to claim 24, said at least one aperture being cut as a notch along one side of a respective one of said boards such that one wall of said aperture is provided by an adjacent board.
 28. The support structure according to claim 24, said at least one aperture comprising a bevel along at least a portion of one edge.
 29. The support structure according to claim 24, said at least one aperture being sized substantially similar to said lifting link to restrict pivotal movement thereof.
 30. The support structure according to claim 24, said at least one aperture being longer in the longitudinal dimension of said board than the width of said link such that pivotal movement of said link is accommodated.
 31. The support structure according to claim 30, said at least one aperture comprising a bevel.
 32. The support structure according to claim 24, said at least one board being constructed of a recycled material such as beetle kill lumber, plastic or rubber.
 33. The support structure according to claim 24 wherein said rod is threaded at one end to accommodate a nut and is bent at another end to retain said rod.
 34. The support structure according to claim 24 further comprising a radio frequency identification tag affixed thereto.
 35. A retractable lifting link to permit lifting a ground covering support structure, said lifting link comprising a lifting eyelet and an elongated slot to enable said lifting link to be secured within an aperture in said support structure by a rod passing therethrough such that movement of said lifting link through said aperture is restricted.
 36. The lifting link according to claim 35 wherein said link is formed as an elongate member rounded at each end, said lifting eyelet being formed at one end and said elongated slot being extending from the other end towards said eyelet.
 37. A ground covering support structure comprising at least one board constructed of a recycled material such as beetle kill lumber, plastic or rubber.
 38. The support structure according to claim 37 further comprising a radio frequency identification tag affixed thereto. 